https://www.bgr.com/2113355/robot-3d-printed-houses-complicated-truth-not-cheap/
Good article to cut through the enthusiasm
A long time ago we had a thread about how one of the huge advantages of site-built over factory-built homes is that a contractor has a low-capital business that can scale up and down with the economy by laying people off, but once you invest in a home factory, you have a high-capital business that needs to make ROI so it needs to run non-stop regardless of the state of the economy.
These capital-intensive site-built methods effectively have the same problem.
Plus, for residential construction, I think people overestimate how much time, labor and expense goes into getting the walls up for a one-story house. A serious framing crew builds out the walls for houses similar to what the 3D printers are doing in a day or two.
Almost all of the cost and time of a 1-story, 1000SF home is something other than framing labor.
One quibble - the cost per square foot is always higher in a small house. Bedrooms, living rooms, media rooms are cheap. Bathrooms and kitchens are expensive. The proportion of kitchen-bath space to bed-living-media room space is always going to drive the cost per square foot up for a small house.
That is probably at least part of the explanation for the American shift to McMansions
In light commercial construction (ex: shopping strip), roughly 30% of the work is done just getting the building out of the ground.
In conventional single-dwelling houses, when it is dried-in you're *maybe* 40% done.
YRMV, but that held true for about 80k sq ft of my experience.